Various methods and devices for monitoring human energy consumption are known in practice. Diet and physical effort planning decisions are made for the individual based on the monitoring results.
U.S. Pat. No. 6,719,667 describes a belt training device equipped with electronic scales that monitor the change of the individual's weight, and the device calculates the amount of energy spent using the installed software. The results are displayed on the screen.
U.S. Pat. No. 7,285,090 describes a device monitoring the ratio of the energy spent and assimilated by an individual using sensors attached to the individual's body. The information is wirelessly transmitted from the sensors to an electronic device where the information is processed by the software installed in the device. Information on the food consumed is entered in the device and the amount of assimilated energy is determined based on this information. The ratio of spent and assimilated energy is determined by processing the total information entered.
Patent application No. US20060253010 describes a sports watch that enables measuring of the energy spent by the individual by using an indirect method, based mainly on the heart rate, weight and age of the individual.
U.S. Pat. No. 6,506,152 describes a method that first calculates the predicted body fat percentage change on the basis of calories consumed from food and calories spent, and after that calculates the energy balance correction factor based on the actual and predicted change of body fat percentage.
Patent application No. US20020193702 describes calculation of the body fat percentage based on a bioimpedance measurement and the individual's individual data, setting the desired body fat percentage as a goal, determining the amount of calories to be spent based on the actual body fat percentage and the body fat percentage set as the goal, and determining the exercising activity required to achieve it.
The drawback of all the above mentioned solutions is the fact that the energy consumption of an individual, and the loss of body fat mass or percentage resulting from that, is determined indirectly based on the amount of energy (calories) consumed and spent, by applying the so-called Harris-Benedict formula, and the results obtained may differ from the actual results. These so-called calorimetric methods also require monitoring of the amount of energy (calories) consumed and spent.
Scales capable of determining the body fat mass and percentage are known, indicating the change of body fat mass and percentage based on two consecutive measurements (e.g. Body Signal scales from the TEFAL brand). The scales can easily give faulty results on the basis of two consecutive measurements—a positive result (decrease of body fat amount) is indicated based on a single change, but at the same time the trend of body fat accumulation continues.